THE STUDY OF PECTIN INFLUENCE ON THE CHANGE IN VISCOSITY AND COLOR OF BEVERAGES WITH NATURAL COLOURANTS DURING STORAGE

Production of functional foods containing such functional ingredients as pectin and anthocyanins is particularly important nowadays. The goal of the given research was to study the effect of high esterified pectin obtained from apples at a dosage of 0.3% on the changes of viscosity and color of drinks based on cherry juice and anthocyanin colourant obtained from black carrot, apple juice and sugar color IV during storage in a dark place at 22 ± 3 °C for 180 days. Optical density was measured using spectrophotometric method at a wavelength of 350 to 700 nm. Mass fraction of solid matter was adjusted using sucrose to reach 10.1 ± 0.7 %, pH for drinks based on cherry juice and anthocyanin colourant obtained from black carrot was adjusted to reach 3.0, and for drinks based on apple juice and sugar color IV – to reach 3.5 in the prepared beverages. The author shows that pectin does not have any significant effect on colour retention in drinks based on cherry juice and anthocyanin obtained from black carrot, and that anthocyanin colourant from black carrots is more stable during storage than the colourant that cherry juice contains. The color of the drinks based on apple juice and sugar color IV without pectin remains almost the same during storage. In the visible spectrum region they have a monotonous graph of the change in optical density, and pectin makes a significant contribution to the final color. It is established that for 180 days of storage kinematic viscosity of the beverages with pectin decreased not more than 12%, that indicates a high level of pectin preservation. According to the results of the research, the author makes a conclusion that the use of pectin to preserve the color of beverages with natural colourants is not practical. It makes sense to use pectin in order to give the beverages functional properties, as well as to increase their viscosity and stability.